Methods of fabricating a polycrystalline diamond compact including gaseous leaching of a polycrystalline diamond body

Abstract

Embodiments of the invention relate to methods of fabricating polycrystalline diamond compacts (“PDCs”) and applications for such PDCs. In an embodiment, a method of fabricating a PDC includes providing a polycrystalline diamond (“PCD”) table in which a catalyst is disposed throughout, leaching the PCD table with a gaseous leaching agent to remove catalyst from the PCD table and bonding the at least partially leached PCD table to a substrate to form a PDC.

What is claimed is: 
     
       1. A method of fabricating a polycrystalline diamond compact, comprising:
 providing a polycrystalline diamond table including a plurality of bonded diamond grains defining a plurality of interstitial regions in which a metal-solvent catalyst is disposed; 
 leaching the polycrystalline diamond table with a gaseous leaching agent to at least partially remove the metal-solvent catalyst from the polycrystalline diamond table; 
 infiltrating the at least partially leached polycrystalline diamond table with a metallic infiltrant from the substrate; and 
 bonding the at least partially leached polycrystalline diamond table to the substrate to form the polycrystalline diamond compact. 
 
     
     
       2. The method of  claim 1  wherein the gaseous leaching agent comprises a mixture of a halogen and at least one inert gas. 
     
     
       3. The method of  claim 1  wherein the gaseous leaching agent comprises a gas selected from the group consisting of at least one halide gas, at least one inert gas, a gas from the decomposition of an ammonium halide salt, a hydrogen gas, a carbon monoxide gas, an acid gas, a gaseous compound including halogen elements, a hydrogen chloride gas, a hydrogen fluoride gas, a nitrogen gas, and mixtures thereof. 
     
     
       4. The method of  claim 1  further comprising:
 prior to the act of bonding, heating the at least partially leached polycrystalline diamond table under partial vacuum conditions to remove at least some leaching by-products therefrom generated during the act of leaching. 
 
     
     
       5. The method of  claim 4  wherein heating the at least partially leached polycrystalline diamond table under partial vacuum conditions to remove at least some leaching by-products therefrom comprises:
 heating the at least partially leached polycrystalline diamond table at a temperature sufficient to sublimate the at least some leaching by-products. 
 
     
     
       6. The method of  claim 5  wherein the temperature is above about 500° C. and below about 700° C. 
     
     
       7. The method of  claim 1 , further comprising:
 prior to the act of bonding, removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching by chemically cleaning the leached polycrystalline diamond table. 
 
     
     
       8. The method of  claim 1 , further comprising reducing a non-planarity of an interfacial surface of the at least partially leached polycrystalline diamond table prior to bonding the at least partially leached polycrystalline diamond table to the substrate. 
     
     
       9. The method of  claim 8  wherein reducing a non-planarity of the interfacial surface of the at least partially leached polycrystalline diamond table prior to bonding the at least partially leached polycrystalline diamond table to the substrate comprises substantially planarizing the interfacial surface to a flatness of about 0.00050 inch to about 0.0010 inch. 
     
     
       10. The method of  claim 8 , further comprising:
 prior to the act of bonding, removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching; and 
 wherein reducing a non-planarity of the interfacial surface of the at least partially leached polycrystalline diamond table prior to bonding the at least partially leached polycrystalline diamond table to the substrate occurs prior to removing the at least some leaching by-products from the at least partially leached polycrystalline diamond table. 
 
     
     
       11. The method of  claim 1  further comprising leaching a portion of the metallic infiltrant present in the infiltrated polycrystalline diamond table to a selected leach depth of about 50 μm to about 800 μm. 
     
     
       12. A method of forming a polycrystalline diamond compact, comprising:
 providing a polycrystalline diamond table including a metal-solvent catalyst distributed throughout and an interfacial surface; 
 exposing the polycrystalline diamond table to a gaseous leaching agent including halide anions to remove at least a portion of the metal-solvent catalyst from the polycrystalline diamond table; 
 reducing a non-planarity of the interfacial surface of the at least partially leached polycrystalline diamond table; 
 after the acts of exposing and reducing, bonding a substrate to the at least partially leached polycrystalline diamond table in a high temperature/high pressure process effective to infiltrate the at least partially leached polycrystalline diamond table with a metallic infiltrant from the substrate and form a polycrystalline diamond compact; and 
 exposing the polycrystalline diamond table of the polycrystalline diamond compact to a gaseous leaching agent including halide anions to remove at least a portion of the metallic infiltrant from the polycrystalline diamond table of the polycrystalline diamond compact. 
 
     
     
       13. The method of  claim 12 , further comprising:
 prior to the act of bonding, removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching by chemically cleaning the leached polycrystalline diamond table. 
 
     
     
       14. The method of  claim 12  wherein reducing a non-planarity of the interfacial surface of the at least partially leached polycrystalline diamond table comprises substantially planarizing the interfacial surface to a flatness of about 0.00050 inch to about 0.0010 inch. 
     
     
       15. The method of  claim 12 , further comprising:
 prior to the act of bonding, removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching; and 
 wherein reducing a non-planarity of the interfacial surface of the at least partially leached polycrystalline diamond table occurs prior to removing the at least some leaching by-products from the at least partially leached polycrystalline diamond table. 
 
     
     
       16. The method of  claim 12  wherein exposing the polycrystalline diamond table of the polycrystalline diamond compact to a gaseous leaching agent including halide anions to remove at least a portion of the metallic infiltrant from the polycrystalline diamond table of the polycrystalline diamond compact includes leaching the at least a portion of the metallic infiltrant present in the infiltrated polycrystalline diamond table to a selected leach depth of about 50 μm to about 800 μm.